The present invention is directed to the discovery of a clean, gas heating and re-circulating pumping system configuration that will quickly and efficiently heat a connected process chamber or process piping section. The useful application of the invention includes the removal of stubborn contaminants such as water vapor and hydrocarbons from the internal surfaces of a process vacuum chamber or process piping system. The invention utilizes the substantial heat generated and subsequently imparted to gas molecules that are agitated as they pass through the inlet and outlet of a dual rotor, multi-lobed, rotary gas compressor. There are a variety of dual rotor, multi-lobed, rotary gas compressors that will perform the gas agitation/heating function of the invention, the most common being dual rotor, multi-lobed, rotary gas compressors such as roots or screw type pumps. The invention was developed using a dual rotor, 60 degree twist, three-lobe rotor, rotary gas compressor, although it is envisioned that there may be alternative pump geometries that will perform the invention functions even more efficiently. The invention heat generation through mechanical molecular gas agitation functions are: 1) Rapid agitation of gas molecules that pass through the inlet and outlet of the compressor/pump creating a substantial rise in gas temperature; 2) Rapid gas throughput to increase the frequency that the gas is agitated in a closed loop gas re-circulation system; 3) Rapid gas agitation and subsequent gas temperature rise with a minimal delta pressure compression ratio between the compressor inlet and exhaust to minimize the amount of energy required to drive the compressor; 4) The ability to operate over a wide pressure range to cover both positive and vacuum pressure applications. The use of dual rotor, multi-lobed, rotary gas compressor to quickly and efficiently raise gas temperature will have broad application as an economical source of convective heat in closed loop piping, commercial convection ovens, process vacuum systems, positive/vacuum pressure dehydration applications, and water and space heating.